import java.util.HashMap;
import java.util.WeakHashMap;

/**
 * Description： TODO
 * Author： 王多鱼
 * CreateTime： 2021/6/21 10:16
 **/
public class WeakHashMapDemo {
    public static void main(String[] args) {
        myHashMap();
        System.out.println("==============");
        myWeakHashMap();
    }
    private static void myHashMap(){
        HashMap<Integer,String> map = new HashMap<>();
        Integer key = new Integer(1);
        String value = "HashMap";
        map.put(key,value);
        System.out.println(map);

        key = null;
        System.out.println(map);
        System.gc();
        System.out.println(map+"\t"+map.size());
    }
    private static void myWeakHashMap(){
        WeakHashMap<Integer,String> map = new WeakHashMap<>();
        Integer key = new Integer(2);
        String value = "WeakHashMap";
        map.put(key,value);
        System.out.println(map);
        key = null;
        System.out.println(map);
        System.gc();
        System.out.println(map+"\t"+map.size());
    }
}
